From Swedish rar meaning "sweet, cute", originally "rare", a word ultimately derived from Latin rarus. This name has been used in Sweden since the latter half of the 19th century.
From Japanese 麗 (ra) meaning "resplendent, lovely, beautiful, graceful" combined with 楽 (ra) meaning "ease, enjoyment, comfort, music". Other kanji combinations are possible". Other kanji combinations are possible. This is most likely inspired by Lala.